DE1277721B - Process for chemically embossing a thermoplastic sheet - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

/ Till

GERMAN #fw PATENTAMT Int. α .:

B 44c

EDITORIAL

German class: 75 b-11

Number: 1277 721

File number: P 12 77 721.8-45 (A 54386)

Filing date: December 15, 1966

Opening day: September 12, 1968

The invention relates to a method for producing a decorative surface coating with a partially cellular or foamed structure, with a thermoplastic decorative surface coating with impressions made by chemical action without the use of mechanical Embossing means are achieved, is to be produced.

The mechanical embossing of foamed or cellular sheets in connection with printing has always led to various problems. So it was difficult to get sharp edges and sharp demarcation lines to get to the embossed areas if you are dealing with foamed bodies had to do. When printing was done in addition to embossing, it was extremely difficult to be accurate Fit between the embossing rollers and the pressure rollers to achieve. The difficulties grew with the width of the embossed and printed sheet.

Thus, there was a need for an improved method of embossing a thermoplastic sheet, and it is the main aim of the invention to satisfy this need and to provide a method in which the embossing and printing of a decorative sheet mesh perfectly.

The invention is based on a method for producing a thermoplastic sheet in which a vinyl resin, a plasticizer for the resin, a blowing agent that is at a temperature above the glass transition temperature of the plasticized vinyl resin and below the decomposition temperature of the Resin decomposes, and an accelerator for lowering the decomposition temperature of the blowing agent is mixed and this mixture is processed into a sheet. To such a sheet chemically too emboss, it is proposed according to the invention to apply a liquid deactivating agent containing a tin salt to the sheet for the accelerator to be applied in the form of a desired pattern and then the sheet to a temperature in the range of 149 To be heated up to 232 ° C.

A lead is advantageously used as the accelerator and / or zinc salt and, as a deactivator, tin chloride or a mixture of an organic tin salt and an inorganic tin salt is used.

The drawing shows an enlarged cross section through a sheet 1 produced according to the invention a support or base 2 and a transparent cover or cover 3.

The thermoplastic resins usable in the present invention are resins capable of forming films and sheets. Such resins are primarily the poly-chemical embossing processes
a thermoplastic sheet

Applicant:

Armstrong Cork Company,

Lancaster, Pa. (V. St. A.)

Representative:

K. L. Schiff, patent attorney,

8000 Munich 9, Bereiteranger 15

Named as inventor:
James Richard Jones,
Lancaster, Pa. (V. St. A.)

Claimed priority:
V. St. v. America December 16, 1965
(514 353)

mers and copolymers of vinyl chloride. Polyvinyl chloride itself is the preferred resin, though Mixed polymers of vinyl chloride with vinyl acetate, vinylidene chloride, other vinyl esters such as vinyl propionate, Vinyl butyrate as well as alkyl-substituted vinyl esters can be used. Vinyl chloride can also be copolymerized with a number of acrylic compounds such as acrylic acid and theirs Esters and the corresponding methacrylates. The thermoplastic resins are those obtained by addition polymerization are formed, in contrast to the normal non-thermoplastic, by condensation resins formed. The glass transition temperature of thermoplastic resins is the temperature at which these resins change from a hard, brittle solid to a flexible solid. At the Increasing the plasticization of the resin decreases the glass transition temperature more. Practically lies the glass transition temperature of the resin close to the initial gelation temperature of that in a plasticizer dispersed resin, even if the initial gelation temperature is rate sensitive is.

The thermoplastic resin, preferably polyvinyl chloride, is, as described above, with a Plasticizers for the resin combined so that the resin can be processed into a sheet. A A convenient method of making a sheet is by making a polyynyl chloride dispersion and the resin with 20 to 130 parts by weight of plasticizer per 100 parts by weight Resin mixed. The manufacture of a plastisol is

809 600/190

a convenient means of making a sheet from a thermoplastic resin. A plastisol is one Mixture of a thermoplastic resin and a plasticizer for the same, the resin in the Plasticizer is distributed in a kind of pulp. Suitable plasticizers are ester type plasticizers such as Dioctyl phthalate, dioctyl sebacate, dioctyl adipate, dioctyl celate, with the octyl group often in the form a 2-ethylhexyl group is present. Other alkyl groups can be used in place of the octyl group to, for example, a plasticizer such as Dibutyl phthalate, dibutyl sebacate, dibutyl adipate and the like. The phosphate esters can also be used, z. B. tricresyl phosphate. The viscosity of the plastisol is controlled to some extent by the selection of the particular plasticizer, the particular resin and the particular one used Quantities of them. Therefore, there is no viscosity range for the respective manufacture of the sheet available to the plastisol.

Instead of a plastisol, the resin can be used in the form of an organosol. In that sense an organosol means a vinyl resin and a plasticizer described above, together with one organic solvent for the vinyl resin, at elevated temperatures. Such solvents can Ketones, aliphatic hydrocarbons, aromatic hydrocarbons and their various Mixtures such as those found in various hydrocarbon fractions used as solvents for vinyl resins are on the market. The amount of solvent in the organosol can range from 10 to 25 parts by weight of organosol per 100 parts by weight of resin. The organic solvent serves to support the processing of the resin slurry to produce a sheet. The usage of plastisols is preferred over that of organosols in the present invention because it reduces the problem of solvent removal.

The blowing agent which can be used in the present invention must be thoroughly distributed in the resin softener mixture be. A wide variety of blowing agents are available for incorporation into thermoplastic resins Market. The preferred blowing agent for polyvinyl chloride is azodicarbonamide, which is normally found decomposes in air at a temperature of about 199 ° C. This propellant is particularly suitable for use in processes according to the invention in view of its high decomposition temperature. Farther this decomposition temperature is easy, as described above, by adding accelerators adjustable. The following table shows other useful blowing agents with the temperature at which they gas Release briskly in dioctyl phthalate.

Propellant

Azobisisobutyrnitrile

N, N'-dimethyl-N, N'-dinitrosotere-

pthalamide

p, p'-oxybis (benzenesulfonylhydrazide) ..
p, p'-oxybis (benzenesulfonylsemi-

carbazid)

Barium azodicarboxylate over

Dinitrosopentamethylenetetramine

(80%)

temperature

115.6

104.4
160

218
249

188

55

60 The useful blowing agents include, in general, the substituted hydrazides, substituted azo compounds and substituted nitroso compounds. The blowing agent will normally be present in an amount of about 0.5 to 15 weight percent based on the weight of the thermoplastic resin. As a general rule, the preferred minimum decomposition temperature of the blowing agent should be about 121 ° C in the composition of the invention, and this should decompose below the decomposition temperature of the resin, which in the case of polyvinyl chloride is about 204 ° C. Normally, however, stabilized vinyl resin compounds will not degrade until elevated temperatures of approximately 232 ° C are reached. The heating of such masses is also a rate controlled process since the mass can be exposed to a relatively high temperature - for example 316 ° C - for a sufficiently short time that the resin itself is not heated above the decomposition temperature. The blowing agents are used in an amount of about 1 to 15 parts by weight per 100 parts by weight of resin. When azodicarbonamide is used as the selected blowing agent, the range will generally be about 2 to 6 parts by weight of azodicarbonamide per 100 parts by weight of vinyl resin.

The fourth component of this mass is an accelerator to reduce the decomposition temperature of the propellant. These accelerators are well known commercially available products. Preferred an accelerator is used for the invention, which is an organic lead salt or an organic zinc salt or a mixture thereof. Lead or zinc octoate in the form of a lead or zinc (2-ethylhexanoate) is preferred, although either the lead or zinc compounds are in the form of a phosphite or other metal salt can be used. It is the metallic portion of the molecule that is responsible for that Acceleration effect is important. These accelerators lower the decomposition temperature of the propellant in the vinyl chloride resin system up to around 27.8 ° C. To be applicable in the present invention To be, the accelerators should be at least the decomposition temperature of the selected blowing agent decrease by about 11 ° C.

The accelerator is often used in approximately the same amount as the propellant. These However, the amount can be changed if necessary to change the decomposition temperature in the Vinyl resin mass by at least about 11 ° C. Related on the metal content of the accelerator salts, the amount of lead or zinc will be in the range of about 1 to 5 weight percent based on the weight of the total amount.

Regarding these four critical components, the resin, the plasticizer, the blowing agent and the accelerator, additional ingredients can be added to the sheet-workable mass such as pigments, dyes or other decorative elements. Depending on the material that can be used and the intensity of the desired color, the amounts of such special additives are normally in the range from small fractions of 1 to 20 percent by weight of the total mass. Relatively small amounts Granulated filler such as clay, limestone or silicate can be added. However, the Mass not to be overly filled as part of the

Mass must expand and form cell-like or foamed areas. Any fillers typically make up less than about 20 percent by weight of the total mass. Small amounts Heat and light stabilizers can also be incorporated, such as the known ones Barium-cadmium salts of long-chain fatty acids, polyols such as pentaerythritol or a-methelylucoside, Nitrogen compounds such as melamine or dicyandiamide, esters such as phenylphthalate, phenylbenzoate, o-Toluene benzoate, triethylene glycol salicylate, certain organic phosphates and their mixtures. Usually used by such stabilizers no more than about 3 percent by weight of the total mass is used.

After thoroughly mixing the various ingredients, the plastisol or organosol becomes too one sheet processed. The plastisol can be knife-coated, roller-coated or otherwise on a carrier or substrate or on a removable carrier on ao to be brought. The carrier can be a steel tape, a rubber tape, paper or a felt with a Be release agent coating. An organosol can be processed in the same way. A relative moderate heating of the plastisol or organosol causes a low melting point and leads to easy to gel and harden the sheet so that it can be removed or otherwise treated can. The heat applied at this stage of the process is insufficient to remove the propellant, even in the presence of the accelerator, decompose. The plastisol or organosol is often applied directly to the Carrier applied, which becomes a permanent part of the surface coating. The carrier , for example, a felt, preferably a rubber-bonded one Asbestos substrate, a vinyl sheet carrier, a cellulose felt or other for surface coatings be a suitable carrier.

The thermoplastic sheet produced in the manner described so far normally has a thickness in the range of about 0.254 to 3.81 mm (excluding the carrier). A propellant is thorough in the sheet distributed in a state that it would with sufficient heating of the sheet to the decomposition temperature of the propellant influenced by the accelerator decomposes and gives off gas.

According to the invention, a deactivating is now applied to the sheet in a predetermined pattern Compound that eliminates the effect of the accelerator applied. If this deactivator comes, which can be applied in a paint or other liquid, with the accelerator in contact, it destroys the effectiveness of this accelerator. As a result, areas 4, to which the deactivator is applied, a foam only at a considerably higher temperature form than the areas 5 free of the deactivator. Then the printed sheet is only on heats a temperature that decomposes the propellant in the areas still containing the accelerator, but those below that for decomposition of the propellant in those treated with the deactivator Areas.

The deactivator should preferably be mixed with a liquid that penetrates the leaf and so takes the deactivator with it and thus brings it into contact with the accelerator. These The carrier liquid with which the deactivator is mixed is preferably a diluent Solvent or plasticizer for the vinyl resin in the plastic sheet. For example, a Mixture of methyl ethyl ketone and dioxane as an excellent carrier for these compounds. Each the various ketones can be used alone or in a mixture, for example ethyl amyl ketone, Methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and their mixtures. The one below still to Desactivator compounds describing them are normally soluble or at least partially soluble in the liquid that is printed or otherwise applied to the lightly gelled plastisol sheet must in order to maximize contact between the joint and that distributed in the plastic sheet To manufacture accelerators.

A carrier liquid containing the deactivator can be applied in the customary manner will. Indeed, the carrier liquid can and can be used as a printing ink also contain binders, dyes, pigments, wetting agents, stabilizers and other compounds, usually found in one color. Such a tinted color will appear when printing the thermoplastic sheet described above in a known manner a colored pattern or drawing generate on the sheet. The subsequent heating in the temperature range specified above there is then foaming only in the areas not brought into contact with this color result. The deactivation of the propellant-accelerator system in the areas where the deactivator-containing paint has been applied will prevent foaming.

As mentioned above, the areas printed with the ink containing the deactivator are in the desired Measure not foamed while the remaining, the propellant accelerator system containing areas are foamed. The use of larger or smaller amounts of deactivator is used to control the foaming possible in the printed areas, so that one if necessary, can achieve embossing with different levels. It is also possible to separate such Areas that are foamed to be printed with an ink that does not contain a deactivator, though this gives rise to problems of the different imprints matching one another. The inks, Both the deactivator-containing and the deactivator-free are normally used in the Applying a pigmented or dye-containing ink film applied thickness. They generally range in thickness from 0.00254 to about 0.508 mm, depending on the ability of the liquid Carrier to penetrate the thermoplastic sheet and depending on the concentration of the deactivator in the liquid carrier. Depending on the activity of the particular deactivator selected, the Deactivator concentration in the printing ink in the range of about 5 to 65 percent by weight of the Total weight of the printing ink.

The deactivator used according to the invention is a tin salt. The tin salt can be bivalent or tetravalent and be organic or inorganic. Mixtures can also be used. Will If organic compounds are used, the organic part should preferably not be particularly large, otherwise a higher concentration of tin salt

in the printing ink or carrier liquid becomes necessary. A useful organic tin salt is Tin formate, although tin maleate and tin mercaptides are useful. Tin salts of organic fatty acids with 1 to 18 carbon atoms can be used. From the inorganic tin salts are the tin chlorides, both bivalent and tetravalent, and those with fluctuating amounts of Water of crystallization, useful. The tin nitrate,

After thorough mixing, the plastisol becomes one in one in a film 0.3048 mm thick Dutch-made asbestos felt sheet is sprayed on, which is normally used as a floor covering substrate will. The plastisol is made by exposure to a temperature of 121 ° C for 4 minutes Gel converted. There is no decomposition of the propellant. When cooling, the gelled lies Plastisol film on the substrate in a state before

sulfates and carbonates as well as mixed organic io the printing with his printing ink allows.

inorganic combinations can also be used. The printing ink can be easily made by simply adding the tin salt to the ink during normal ink manufacture. If a mere carrier liquid such as a ketone is used alone so that no ink or dyes remain in the printed areas, then the liquid carrier and the tin salt are simply mixed to apply the deactivating liquid in the desired pattern. Depending on the type of application of such a liquid, the rate of evaporation of the carrier liquid can be controlled by adding liquids with higher boiling points. For example, cyclohexanone mr "n \ may be a solution in methyl ethyl ketone was added 25 Sn (COO) ₂ ..

so that the carrier liquid is slower to move. SnCl ₂

steams. Similarly, the drying SnCl ₁ · 5 H "O, the ink can be controlled by using different ketones having different boiling points speed.

If the surface covering produced by the present process is used as a floor covering, so an additional wear surface 3 can be applied to the entire sheet before the final,

A series of six color masses was produced with the following composition:

Components

Vinyl chloride-vinyl acetate copolymer, 14 weight percent
Vinyl acetate, pigmented

Methyl ethyl ketone

5 5

Tin mercaptide (Thermolite 31) 40

SnCL

2H ₂ O

Parts by weight 2 13 14 15

15th

25th

20th

25th

20th

Patterns were printed on the gelled plastisol sheet using each of these colors. the The drying speed of the different colors was simply controlled by replacing the methyl ethyl ketone, partially or completely by

the amount of other ketones such as methyl isobutyl causing foaming in the unprinted parts of the sheet Heating can be applied. Is ketone, ethyl amyl ketone and cyclohexanone. The Ver-' the deactivator-containing mass once in a decorative print pattern was a beach pebble pattern, relative pattern on the surface of the thermoplastic. The damp film of the printed color was indistinct If the sheet is applied, the sheet must be 0.0025 mm thick. The color was on the Applying moderate heat to be dried, 40 air dried.

without causing foaming. A colorless or printed gelled plastisol sheet then became

colored coating of a thermoplastic resin with an organosol coating to make the tatcan then on the entire sheet in a known manner neuter wear layer 3 on the end product be sprayed on, knuckled or rolled. To bring this up. A number of polyvinyl transparencies have been used Coating is the last coat and 45 chloride resins in the composition that will be different over each previously put on the thermoplastic which clear coatings. The fol sheet applied imprint. The heat causes the resin to melt and decompose the propellant-accelerator combination; the clear top coat 3 also melts and becomes a 50 integral, both the raised, foamed parts and the low, non-foamed parts of the sheet covering component of the finished product. In the following example, all data are parts by weight and percentages by weight.

For example, a plastisol was produced with the following composition:

The following masses were preferred:

Components

Polyvinyl chloride

Dioctyl phthalate

Epoxidized soybean oil

Barium, calcium, lead phosphite stabilizer

Components

Polyvinyl chloride =.

Dioctyl phthalate

Epoxidized soybean oil

Zinc (2-ethylhexanoate), 9.6% zinc .. Azodicarbonamide, 60% in

Dioctyl phthalate

Titanium dioxide, 50% in dioctyl phthalate

Parts by weight of ethylene glycol, molecular weight

about 200

HC solvents, mainly

η aliphatic

Parts by weight

100

20th

2 12

65 The colorless coating was applied to the printed gelled plastisol sheet with a knife. 4.2 The colorless coating was caused by gelling

8.6 121 ° C dried for 2 minutes.

The entire system was then melted and foamed by making the coated, printed, Gelled plastisol sheet 1 on a carrier 2 was subjected to a temperature of 188 ° C. for 3.5 minutes. The product obtained was then cooled.

"The thickness of the unexpanded areas was measured on these and other samples. Around these To determine the thickness, the sample was cut open and the cross-section examined. The fully inflated unprinted areas 5 represented the maximum height of the cell-containing vinyl resin on average In the printed, not so strongly expanded areas 4, the average was measured to to maintain the thickness in the printed areas. The thickness of the printed areas compared to the Thickness of the fully expanded areas was about 6: 100 for a very thin film of paint, the tin mercaptid about 65% for a preferred ink film with a mixture of stannous chloride and tin maleate contained the following formula:

Components

Vinyl chloride-vinyl acetate copolymer, 14 weight percent
Vinyl acetate

Cyclohexanone

Tin (II) chloride

ZJnn (n) -malleate (Thermolite 32)

Parts by weight

35
20th
22.5
22.5

Claims (4)

Patent claims: 1. A method of chemically embossing a thermoplastic sheet using a vinyl resin, a plasticizer for the resin, a blowing agent that is at a temperature above the glass transition temperature of the plasticized vinyl resin and decomposed below the decomposition temperature of the resin, and an accelerator for lowering the decomposition temperature are mixed and this mixture processed into a sheet is characterized in that a liquid containing a tin salt is applied to the sheet Deactivating agent for the accelerator applied in the form of a desired pattern and then heating the sheet to a temperature in the range of 149 to 232 ° C. 2. The method according to claim 1, characterized in that the accelerator is a lead and / or zinc salt is used. 3. The method according to claim 1 or 2, characterized in that tin chloride is used as the deactivator is used. 4. The method according to claim 1 or 2, characterized in that a mixture is used as the deactivator an organic tin salt and an inorganic tin salt is used. Considered publications:
German Auslegeschrift No. 1109 876;
U.S. Patent Nos. 2,676,928, 2,708,661. 1 sheet of drawings 809 600/190 9.68 © Braidesdruckereijerlin